1. Technical Field
The present inventive concepts relates to a semiconductor device and a method for fabricating the same.
2. Description of the Related Art
As a feature size of transistors is reduced, a gate and a channel formed under the gate are becoming smaller. Therefore, methods to increase the capacitance between the gate and the channel and improve operating characteristics of the transistors are being developed.
One of these methods includes adjusting a threshold voltage by controlling a work function of a transistor. The work function of the transistor may be controlled by, for example, implanting ions into a channel region of the transistor. However, as the feature size of transistors is reduced and a shape of transistors becomes three-dimensional, it is becoming difficult to control the distribution of implanted ions.